Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Nomeie o número total de painelistas para 19 de janeiro de 2007.
 ###Tabelas: CREATE TABLE main_transmitters (main_transmitters_id AUTO_INCREMENT PRIMARY KEY, Region served VARCHAR, ch 1 VARCHAR, On-air date VARCHAR, Analogue Power VARCHAR, Digital Power VARCHAR, Analogue HAAT VARCHAR, Digital HAAT VARCHAR, Transmitter Location VARCHAR) CREATE TABLE 2006_summer_season (2006_summer_season_id AUTO_INCREMENT PRIMARY KEY, Japanese Title VARCHAR, Romaji Title VARCHAR, TV Station VARCHAR, Episodes INT, Average Ratings VARCHAR) CREATE TABLE highest_percentage_of_pole_positions_in_a_season (highest_percentage_of_pole_positions_in_a_season_id AUTO_INCREMENT PRIMARY KEY, Driver VARCHAR, Season INT, Races INT, Poles INT, Percentage VARCHAR) CREATE TABLE discus_throw (discus_throw_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Athlete VARCHAR, Country VARCHAR, Distance (metres) VARCHAR, Points VARCHAR, Adjusted Points INT) CREATE TABLE series_4 (series_4_id AUTO_INCREMENT PRIMARY KEY, Episode Number INT, Air Date VARCHAR, Guest Host VARCHAR, Musical Guest (Song performed) VARCHAR, Who knows the most about the guest host? panelists VARCHAR, Coat Of Cash Wearing Celebrity VARCHAR)  
SELECT COUNT Who knows the most about the guest host? panelists FROM series_4 WHERE Air Date = 19 January 2007